1. Field of the Invention
Embodiments of the present invention relate to a light emitting device, a light emitting device package, and a lighting system including a current blocking layer.
2. Discussion of the Background
Light emitting devices (LEDs) are semiconductor devices configured to convert a current into light. In addition, various LEDs including green LEDs are being used as light sources in electronic devices such as communication devices. For example, nitride semiconductors have a high thermal stability and wide band gaps, and are combined with other elements such as In and Al to form semiconductor layers for emitting green, blue and white light.
In addition, because it is easy to adjust wavelengths emitted from nitride semiconductors, nitride semiconductors are used in high power electronic devices including LEDs. Further, a light emitting structure includes a second conductive type semiconductor layer, an active layer, and a first conductive type semiconductor layer. In a vertical type light emitting device, a second electrode applying power to the first conductive type semiconductor layer is vertically disposed, and electrons and holes injected to respective electrodes flow into the active layer and are coupled to generate light.
The generated light is then emitted outward. However, a portion of light is absorbed into the electrodes at both ends, or disappears in the light emitting device, and thus is not emitted outwards. In more detail, the light emitted under an n type electrode region is reflected by an n type electrode, and is absorbed into the device. The absorbed light also generates heat in the light emitting device, which negatively affects the service life and reliability of the light emitting device.